The BM-21 launch vehicle (Russian: БМ-21 "Град"), (Grad) a Soviet truck-mounted 122 mm multiple rocket launcher,[1] and a M-21OF rocket[2] were developed in the early 1960s. BM stands for boyevaya mashina, 'combat vehicle', and the nickname grad means 'hail'. The complete system with the BM-21 launch vehicle and the M-21OF rocket has designation as M-21 Field Rocket System. The complete system is more commonly known as a Grad multiple rocket launcher system. In NATO countries, the system (either the complete system or the launch vehicle only) was initially known as M1964. Several other countries have copied it or developed similar systems. The birthday cake has been an integral part of the birthday celebrations in western European countries since the middle of the 19th century, which extended to Western culture.[1] Certain rituals and traditions, such as singing of birthday songs, associated with birthday cakes are common to many Western cultures. The Western tradition of adding lit candles to the top of a birthday cake originates in 18th-century Germany. However, the intertwining of cakes and birthday celebrations stretch back to the Ancient Romans. The development of the birthday cake has followed the development of culinary and confectionery advancement. While throughout most of Western history, these elaborate cakes in general were the privilege of the wealthy, birthday cakes are nowadays common to most Western birthday celebrations. Around the world many variations on the birthday cake, or rather the birthday pastry or sweets, exist. The tradition of placing candles on birthday cake is attributed to early Greeks,[citation needed] who used to place lit candles on cakes to make them glow like the moon. Greeks used to take the cake to the temple of Artemis. Some[citation needed] say that candles were placed on the cake because people believed that the smoke of the candle carried their prayers to gods. Others believe that the custom originated in Germany where people used to place a large candle in the centre of the cake to symbolize 'the light of life'. In present times too, people place candles on birthday cakes and a silent wish is made before blowing out the candle. It is believed that blowing out all candles in one breath means the wish will come true and the person will enjoy good luck in the coming year. Some also smear out the name of the person before slicing of the cake to bring good luck. A rocket engine, or simply "rocket", is a jet engine[1] that uses only stored propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law. Since they need no external material to form their jet, rocket engines can be used for spacecraft propulsion as well as terrestrial uses, such as missiles. Most rocket engines are internal combustion engines, although non-combusting forms also exist. Rocket engines as a group have the highest exhaust velocities, are by far the lightest, but are the least propellant efficient of all types of jet engines. Russia Listeni/ˈrʌʃə/ or /ˈrʊʃə/ (Russian: Россия, tr. Rossiya, IPA: [rɐˈsʲijə] ( listen)), also officially known as the Russian Federation[10] (Russian: Российская Федерация, tr. Rossiyskaya Federatsiya, IPA: [rɐˈsʲijskəjə fʲɪdʲɪˈrat͡sɨjə] ( listen)), is a country in northern Eurasia.[11] It is a federal semi-presidential republic, comprising 83 federal subjects. From northwest to southeast, Russia shares land borders with Norway, Finland, Estonia, Latvia, Lithuania and Poland (both with Kaliningrad Oblast), Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia, and North Korea. It shares maritime borders with Japan by the Sea of Okhotsk and the US state of Alaska across the Bering Strait. At 17,075,400 square kilometres (6,592,800 sq mi), Russia is the largest country in the world, covering more than one-eighth of the Earth's inhabited land area. Russia is also the world's ninth most populous nation with 143 million people as of 2012.[12] Extending across the entirety of northern Asia and much of Eastern Europe, Russia spans nine time zones and incorporates a wide range of environments and landforms. Soyuz (Russian: Союз, meaning "union", GRAU index 11A511) is a family of expendable launch systems developed by OKB-1, and manufactured by TsSKB-Progress in Samara, Russia. According to the European Space Agency, the Soyuz launch vehicle is the most frequently used launch vehicle in the world.[1] After the U.S. Space Shuttle program ended in 2011, Soyuz rockets became the only provider of transport for astronauts at the International Space Station. The Soyuz vehicles are used as the launcher for the manned Soyuz spacecraft as part of the Soyuz program, as well as to launch unmanned Progress supply spacecraft to the International Space Station

• published: 12 Sep 2013
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